Modbus TCP module issues with Discrete Inputs


Having issues with bad tag quality for tags coming from modbus tcp module, specifically discrete inputs. I have other holding registers from the same device and those tags are fine and good quality. I have tried changing settings such as disabling span gaps and messed around with the tag group settings. Nothing works. I’m hoping someone else has seen this before and has some advice. If I go to opc quick and do a read for one of the bad tag addresses it says good, if I subscribe in quick client is shows bad.



Wireshark will reveal all.

I don’t claim to know the ins and outs of wireshark. What exactly would I be looking for in trace?


Record a single successful read, then a subscribe that fails. Feel free to post it here with info about what addresses you’re testing, IP addresses, etc…

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